The role of endothelial microparticles in autoimmune disease patients with Raynaud's phenomenon

Raynaud's phenomenon (RP) is a microvascular disorder characterized by episodic peripheral vasospasm and ischemia and is commonly found in patients with autoimmune diseases (AID). The vasomotor homoeostasis and endothelial cells damage are involved in RP. Endothelial microparticles (EMPs) may act as a biomarker for endothelial damage. The aim of this study is to investigate the correlation between the levels of microparticles (MPs) and microvasculopathy in AID with RP.

Thirty-seven patients with AID and RP (RP group) and 27 patients with AID but without RP (non-RP group) were enrolled. The microvasculopathy score of RP was graded by nailfold capillary microscopy. The plasma levels of MPs were measured by flow cytometry utilizing specific labels for endothelial MPs (CD105 and CD144) and annexin V staining for phosphatidylserine bearing-MPs (annexin V+MPs).

The levels of circulating EMPs (CD105+ p = 0.005, CD144+ p = 0.004), and the annexin V+ MPs (p < 0.001) were significantly elevated in the RP group compared with the non-RP group. Moreover, the high microvasculopathy scores were closely related with annexinV+ MPs levels in the RP group (p = 0.041).

Levels of circulating EMPs and annexin V+ MPs are elevated in AID patients with RP indicate the endothelial damage and endothelial dysfunctions. In addition, levels of annexin V+ MPs can predict the severity of microvasculopathy in AID with RP.